Drill



Sept' 25, 1962 w. N. PRINCE 3,055,442

Arma/seg.

Sept 25, 1962 w. N. PRINCE 3,055,442

DRILL Filed Nov. 4, 1960 2 Sheets-Sheet 2 MA 715 M .PQM/CE,

INVENTOR.

Arrow/gig@l United States Patent Otlice 3,055,442 Patented Sept. 25, 1962 3,055,442 DRILL Walter N. Prince, 1717 N. Vine St., Suite 7, Hollywood, Calif. Filed Nov. 4, 1960, Ser. No. 67,404 '7 Claims. (Cl. 175-230) This invention relates to drills and more particularly to drills of the type wherein the drilling is accomplished by means of a stream of abrasive material being discharged against the surface -through which an opening or borehole is to be drilled. Still more particularly, this invention relates to drills for drilling deep wells for oil, gas and the like, as well as drilling into the side of hills to open water springs, etc., and for drilling holes through composite and non-composite materials.

One of the conventional methods of drilling oil wells is by means of a rotary drill bit mounted on the end of a drill shaft which extends down the borehole from the ground surface. The drill shaft is rotated at the ground surface and the rotary motion is transmitted by the drill shaft to rotate the drill bit at the bottom of the borehole. The drill bit has cutters thereon which cut and distintegrate the formation at the lower end of the borehole, and the cuttings are carried upwardly to the ground surface by means of a stream of ilushing fluid which is often referred to as drilling mud and which is pumped down- Wardly through the drill shaft in order to flush the cuttings up the space between the wall of the borehole and the drill shaft. The drilling mud also serves to cool and lubricate the drill bit in order to prolong Ithe life of the drill bit.

One of the disadvantages of the above described prior art method is that as the borehole deepens, the length of the drill shaft or stem must be increased, which, of course, increases the weight which must be supported by the drill bit which rests on the bottom of the borehole. Furthermore, the twist in the drill shaft increases due to the transmission of the torque over an increased length. When the drill bit becomes dull or requires changing for other reasons, the drill bit along with the drill shaft must oe pulled to the ground surface.v Accordingly, the changing of bits is a slow operation, requiring time and considerable effort and involving the use of heavy and powerful machinery.V Very often, the drill bit becomes jammed in the borehole when it is being pulled to the ground surface.

Another disadvantage of the previously described method is that complicated and expensive pumping equipment must be provided at the derrick site to pump the drilling mud down the hollow drill shaft at pressures ranging as high as 1500 pounds per square inch.

The present invention overcomes the aforementioned disadvantages by providing a non-rotating drill head which may be cable supported so that it is not necessary to rotate a heavy, lengthy drill stem or to remove great lengths of pipe for bit replacement or repair.

'Ihe basic principle of the present invention is that it involves the use of granulated particles of abrasive material and compressed duid each of which is fed to a nozzle in the drill 'assembly by means of a single conduit or a plurality of conduits and allowed to mix in the nozzle so that the abrasive particles become entrained in the fluid issuing from the nozzle whereby the abrasive particles are accelerated to a high velocity in the jet stream of the nozzle and thereby acquire considerable kinetic energy -so that when they impinge against the formation through which a hole is to be drilled, they strike the formation with a cutting, chipping and peening action and distintegrate the formation to effect a drilling action.

Means are also provided by the present invention to withdraw the spent abrasive particles and the cuttings removed frorn the `formation by means of a separate duct leading from the vicinity of the cutting zone to pumping equipment at the ground surface.

A iblow-out preventer forms an important part of the present invention and provides means responsive to excessive pressures in the borehole to securely hold the drill assembly in the borehole when a blow-out occurs.

An object of the present invention is, therefore, to provide a well drill which does not employ conventional drill bits, but operates by means of discharging a high velocity stream of abrasive material against the bottom of the well to cut and distintegrate the formation at the bottom of the well.

Another object of the present invention is to provide a drill whereby the abrasive material used for cutting and the waste material removed from the bottom of the well by the cutting, chipping and peening action of the abrasive material may lbe quickly and efficiently removed without requiring heavy and complicated pumping and filtering equipment.

Another object of the present invention is to provide a well drill which does not require a torque-transmitting drill stem to operate a drill bit.

Another object of the present invention is to provide a drill whereby a stream of abrasive material is discharged in such a manner that the maximum cutting efficiency is attained, and a smooth-sided borehole is obtained.

Still another object of the present invention is to provide a blow-out prevention means so that if an oil or gas blow-out occurs during the drilling operation, the drill will remain in position in the borehole, thus preventing the escape of iiuid toward the ground surface.

A still further object of the present invention is to provide a drill which can be readily lowered into the drilled well and withdrawn therefrom without the danger of the drill becoming lodged iu the bore of the well.

These and other objects and advantages of the present invention will become apparent in the following description when read in conjunction with the accompanying drawings wherein like reference numerals designate similar parts throughout and in which:

lFIGURE l is a side elevational View of the drill in cross-section showing the operation of the drill as applied in drilling a well;

FIGURE 2 is a transverse sectional view taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a transverse sectional view taken along the line 3-3 of FIGURE l;

FIGURE 4 is a perspective fragmentary View showing, in enlarged scale, one of the ngers which is part of the blow-out preventer means on the drill as shown in FIG- URE 1;

FIGURE 5 is a side elevational section view of a rotatable nozzle adapted to Ibe tted to the drill shown in FIG- UREI l; and

FIGURE 6 is a view of a transverse section taken along the line 6--6 of FIGURE 5.

Referring now to the drawings, and specically to FIG- URE l, one embodiment of the invention is shown in drilling position in the borehole. The hollov.r shroud indicated by the reference numeral 12 is of uniform outer diameter along its entire length. The inner surface 14 of the shroud is stepped to provide an annular extension 16 which is internally threated at 18 for attachment to the threaded end 20 of a shroud hanger which is designated generaly by the reference numeral 24.

Shroud hanger 24 comprises a cylindrical base or shank Z5 having an externally threaded end 20 as previously described. A plurality of spokes 26 are joined at their lower ends to the inner surface of the shank 25 and at their upper ends are united integrally with a support member 28.

For the purpose of preventing blow-out damage, a blowout preventing assembly is mounted on the support member 23 and comprises a plurality of fingers 30 slotted as at 32 to accommodate a spring 34 which is held in position within the slot 32 by means of a bolt or rivet 36. The bolt or rivet 36 fits through holes or pivot bearings in the fingers 30 and passes through the finger support member 28 to hold the fingers 30 against flat portions 38 on the finger support member. Each of the bolts 36 serves to hold one pair of fingers 30 to the support member 2S.

The support member 28 is provided with bosses or protrusions 40 which extend outwardly from the surface of the support member 28 and are located adjacent the pivot end 42 of each of the lingers 30 to prevent the fingers 30 from rotating downwardly beyond a position perpendicular to the axis of the finger support member 2S. Another purpose served by the protrusions 40 is in providing bearing points for the ends 44 of the wire elements which form the coil springs 34. The other end 46 of each wire element bears against a surface 4S which defines an edge of the slot 32 in each of the fingers 30. Thus it will be seen that the tension of the springs 34 urge the fingers 30 pivotally downward so that the ends 50 of the fingers 30 bear against the surface of the sides of the well bore; and therefore, when a gas or oil blow-out occurs, the force exerted against the drill tending to move it upwardly toward the ground surface will cause the ends 50 of the fingers 30 to bite into the surface of the well bore as indicated at 52. It will be seen that any force tending to drive the drill upwardly will urge the fingers 30 to penetrate more deeply into the wall of the borehole.

Concentrically disposed within the shroud hanger 24 is a sleeve 53 which is free to slide axially relative to the shroud hanger 24. The sleeve 53 is provided with slots 54 through which pass the spokes 26. There is sufiicient clearance between the spokes and the surface of the ma terial of the shroud hanger 24 defining the slots S4, to permit the sleeve 53 to slide relative to the spokes 26. The upper end of the sleeve 53 is provided with a plurality of holes 56 through which are fitted rings 58 to which are connected cables or chains 60. The cables 60 are joined to a link 62 to which is connected a cable 64 for raising and lowering the drill into a borehole.

A ridge 66 extends inwardly from the inner Surface `14 of the hollow shroud 12 to provide a stop against which the lower end of the sleeve 53 may bear when the sleeve 53 is in its extreme downward position relative to the spokes 26.

It will be obvious that as a pull in the upward direction is applied to the cable 64, the sleeve 53 will slide upwardly and the upper edge of said sleeve 53 will engage the fingers 30. Continued pull on the cable 64 will overcome the tension of the springs 34 on the fingers 30 and thereby moving the fingers 30 inwardly so that they are enclosed within the sleeve 53 as indicated by the dotted lines designated by the reference numeral 68. Thus it will be seen that the fingers 30 are retained by the sleeve 53 while the drill is being lowered into a borehole and during the operation of pulling the drill upwardly through the borehole. During the drilling operation, the tension on the cable 64 may be released to permit the sleeve 53 to slide downwardly against the ridge 66 thereby releasing the fingers 30 so that the fingers 30 may pivot outwardly under tension of the springs 34 to engage the wall of the borehole. As the drill descends during the drilling operation, the outer ends of the fingers are free to slide downwardly along the wall of the borehole.

When drilling through certain earth strata where the danger of a blow-out is not probable, the shroud hanger 24 and the sleeve 53 may be removed from the drill assembly by separating them at the threaded ends 18 and 20, and the rings 5S may be secured in the openings 70 in the shroud 12. Furthermore, it is contemplated here that the cables 60 and 64, and the rings 58, may be replaced by a threaded tubular shaft or drill stem (not shown) joined to the shroud 12 at the threaded end 18 to support the drill for drilling a horizontal borehole.

The inner surface 14 of the shroud 12 is stepped as at 72 to provide a shoulder 74 against which is fitted a plate 76. An annular insert 78 of generally harder material than that of the shroud 12 is inserted into the shroud 12 and bears along one edge against the plate 76. The plate 76 is provided with a central threaded nozzle opening into which is threaded a nozzle 80. Threaded into the upper end of the nozzle 80 is a fitting 82 to which are connected two conduits 34 and 86. The conduit 86 is inside the conduit 84 and concentric therewith for a distance extending upwardly from the nozzle 80. At a juncture S8, the conduit 86 extends through the wall of conduit 34 and the two conduits continue separately upward.

The plate 76 is provided with a plurality of exhaust openings 90 which lead into an annular space 92 formed by an inner baffle 94 and a duct 96. The bafiie 94 is welded or by other means secured to the plate 76 as at 98 and extends upwardly from the plate 76 and then tapers toward the juncture SS. The duct 96 is concentric with conduits 84 and 86 and is secured at 100 to the plate 76 and extends upwardly at a uniform diameter then tapers, as at 102, to a smaller diameter and continues upwardly through the sleeve 53 to the ground surface.

The conduits 84 and 86 emerge from the duct 96 at 104 and 106 respectively and continue upwardly through the sleeve 53 to the ground surface.

The webs 107 which define the exhaust openings 90 in the plate 76 are elliptical in cross-section to provide a smooth entry of the cuttings flowing from the space below the plate 76 into the duct 96. The nozzle 80 has an internal configuration, as shown best in FIGURE l, to provide the maximum velocity and cutting efciency.

In operation, the grit or abrasive material is conducted by the conduit 84 from the ground surface to the nozzle 80 either under pressure from pumping equipment at the ground surface or allowed to flow due to the influence of gravity.

Air at a high velocity is introduced into the nozzle 80 by the conduit 86 leading from pumping means at the ground surface to the nozzle.

By virtue of the ejector principle, the abrasive material which is substantially in the form of granulated particles is introduced into the nozzle 80` and accelerated to approximately the velocity of the air flow from the conduit 86.

The abrasive particles, indicated by the numeral 108, are discharged from the nozzle '80 and impinge against the bottom of the borehole with a cutting, chipping and peening action which disintegrates the formation at the bottom of the well. The material which is cut and chipped away is sucked up through the exhaust openings 90 into the duct 96 Where it continues to be drawn upwardly through the tapered portion 102 to the ground surface. For this purpose, the duct 96 may be connected with a low pressure outlet, as a vacuum means, on the surface.

Because of the rapid removal of the abrasive particles from the bottom of the borehole, before they can accumulate on the bottom, the drill is rendered more effective and the abrasive particles are not cushioned or their movement impeded. This also is helpful in keeping air pressure at the bottom of the hole at a minimum, and this low air pressure provides less resistance to passage of the abrasive particles.

In FIGURES 5 and 6I a rotary type nozzle is shown which may be readily fitted to the plate 76 simply by unthreading the fitting 82 from the nozzle 80, removing the nozzle 80 from the plate 76 and replacing it with the rotatable nozzle shown in FIGURES 5 and 6. The titting 32 containing the ends of the conduits `84 and 86 is threaded into an adapter sleeve 110 which is threaded to an annular shank 112 having external threads thereon to adapt it for threading into the plate 76.

The annular shank 112 extends below the lower surface of the plate 76 and is journalled in a bearing designated generally by the reference numeral 114. The inner race 116 of the bearing is secured stationary to the annular shank 112 and the outer race 118 is press-fitted or by other means secured to the stepped wall portion 120 of the rotatable nozzle body 122.

Thus it will be seen that the nozzle body 122 is free to rotate relative to the plate 76.

The nozzle body 122 is provided with an opening 124 communicating with a central opening 126 in the annular shank 112 and with the opening in the fitting 82. The opening 124 diverges into a plurality of discharge openings 128 and 130 which slope spirally downward in opposed directions to the bottom end of the nozzle body 122 to have both downward and tangential components of direction.

The outlet diameters of the passages 128 and 130 are of slightly different diameters thereby one is constrained to conduct a smaller volume of abrasive material than the other and in that they discharge in opposed directions, the speed of angular rotation of the nozzle will depend upon the discharge differential, thereby, by providing outlet passages of different diametral sizes, the whirling speed of the rotatable nozzle body can be controlled.

Thus it will be seen that when, for example, a drilling ,operation is being performed in, say, hard rock or granite, a rotatable nozzle can be chosen which will have a low whirling speed thereby concentrating the abrasive particles at a point for a longer period of time. In softer material, a nozzle body could be chosen which would rotate faster.

The principles and structures of this invention, as embodied in the two specific examples illustrated and described herein, are effective to provide improved drilling techniques in a wide variation of utilization of fluids, fluid pressures and grit sizes. However, for deep well drilling operations, it is considered advantageous that air be used as the iiuid and that air velocities in the range of 6000-9009 feet per minute be utilized. Such velocities are readily attainable. Thus, it is known that a velocity of 6000 feet per minute may be derived in hose of oneinch inner diameter at pressures of 90-100 pounds per square inch when 50 cubic feet per minute of air is passing through the hose.

It is also considered preferable that grit sizes be closely regulated since variation in grit sizes will result in irregular cutting patterns.

It will be obvious that the present invention possesses unique and novel capabilities for drilling holes. It does not involve heavy complicated torque transmitting elements and is light in weight as compared to conventional types of drills of the rotary bit type. Furthermore, it is adapted to long periods of use and can be readily and easily withdrawn from the borehole when sampling operations are to be carried out. Only the portions of the drill exposed to the flow of the abrasive particles need be of a harder material than the outer parts of the drill construction so that the use of hard materials which are sometimes more costly is kept at a minimum.

As the borehole deepens and is blasted to the desired diameter, the drill descends and the shroud prevents the wall of the borehole from enlarging in that it protects it from recocheting particles of abrasive, whereby a smooth well bore is maintained.

The length of the shroud is such that the nozzle is constrained to follow a straight path. Should the formation at the bottom of the borehole be of uneven hardness, the shroud will prevent tilting of the drill.

Obviously, many variations of the above described invention may be created without departing from the spirit of the invention. It is therefore -to be understood that the invention is not intended to lbe limited by the specific illustrated examples disclosed herein but rather by the language and scope of the appended claims.

What is claimed is:

1. Drill means comprising a shroud adapted to be supported in a borehole, a plate iixed in said shroud above the lower end thereof, said plate having a nozzle opening and a plurality of radially outwardly disposed exhaust openings, a nozzle secured in said nozzle opening and having its inlet end above said plate and its ejection end below said plate, a pair of concentric conduits in sealed communication with the inlet end of said nozzle, one of said conduits being adapted to be attached to a source of supply of granulated abrasive material, the other of said conduits being adapted to he attached to a source of uid under pressure, a duct disposed radially outwardly of said exhaust openings and attached to the upper surface of said plate, said duct being adapted to be attached to a source of relatively low pressure fluid.

l2. Drill means according to :claim 1, wherein said nozzle is in xed relationship to said plate and the ejection end of the nozzle is directed axially downwardly into the borehole.

3. Drill means according to claim 1, wherein said nozzle is mounted on said plate for rotation about a longitudinal axis, yand wherein the ejection end of the nozzle has at least one downwardly directed discharge opening which is directed in part tangentially whereby the nozzle will rotate in response to the reaction forces created by the passage of pressure iiuids therethrough.

4. Drill means according to claim 1, wherein `said nozzle is mounted on said plate for rotation about a longitudinal axis, and wherein the ejection end of the nozzle has at least two downwardly directed discharge openings of different size which are directed in part tangentially in non-interfering directions from one another, the directions of the tangential components being opposite to one another, whereby the forces tending to rotate the nozzle in response to the passage of pressure fluid through said openings will he controlled by the difference in size and direction of said `discharge openings.

5. Drill means for drilling -a borehole comprising a shroud, a plate fixed in said shroud above the lower end thereof, said plate having a nozzle opening tand la plurality of radially outwardly disposed exhaust openings, a nozzle secured in said nozzle opening and having its inlet end above said plate and its ejection end below said plate, Ia pair of concentric conduits in sealed communication with the inlet end of said nozzle, one of said conduits being adapted to -be attached to ia source of supply of granulated abrasive material, the other of said conduits being adapted to be attached to a source of iiuid under pressure, ta duct disposed radially outwardly of said exhaust openings and attached to the upper surface of said plate, said duct being adapted to be attached to a source of relatively low pressure fluid, a shroud hanger connected to the upper end of the shroud, said shroud hanger having a plurality of spokes extending inwardly and upwardly to la centrally located support member integral with said spokes, a plurality of fingers pivotally mounted on said support member `and adapted to be swung outwardly thereof, said ngers being lof a length greater than vthe radius of `the borehole, spring means urging said fingers into contact with the wall surface of the borehole, whereby said fingers will ride upon the surface of the borehole during drilling but will be driven into locking engagement with the wall surface of the borehole by excessive forces tending to blow the drill means out of Ithe borehole.

6. Drill means `according to claim 5, further comprising a sleeve slidably disposed within said shroud hanger, slots in sai-d sleeve to accommodate said spokes whereby said sleeve is free to relative axial movement `and cable means supporting said sleeve whereby said sleeve may be raised to force said fingers inwardly out of engagement with the wall surface of the borehole.

7. A drill according to claim 6, further characterized in that the shroud is provided with a threaded end for threading engagement with the shroud hanger, said shroud and shroud hanger having vsubstantially the same outer diameters, said shroud having an inwardly directed ridge disposed on its inner surface and integral therewith for enl0 gagement with the slidable sleeve to limit relative downward movement of said sleeve, said spokes limiting relative upward movement of said sleeve, openings in the upper end of said sleeve, support rings in said openings, cables connected to said rings, said cables converging to a link and connected thereto, said link being connected t0 la cable extending upwardly through the boreholes.

References Cited in the le of this patent UNITED STATES PATENTS 1,852,903 `Salmon Apr. 5, 1932 1,853,379 Rotinot Apr. 12, 1932 2,708,102 Freeman et al May 10, 1955 2,720,834 Davis Oct. 18, 1955 2,770,924 Mead et al. Nov. 20, 1956 2,885,184 Ortlol et al. May 5, 1959 

